Inorganic-organic phosphate ceramics and coatings

ABSTRACT

This disclosure relates to an inorganic-organic metal phosphate ceramic coating from the reaction of an inorganic phosphate of the formulas (i) A m (H 2 PO 4 ) m .nH 2 O or (ii) AH 3 (PO 4 ) 2 .nH 2 O; where A is ammonium or an m-valent metal element; m=1, 2, or 3; and n is 0 to 25; and at least one metal oxide or hydroxide represented by the formula B 2m O m  or B(OH) 2m , where B is a 2m-valent metal; and m=1 or 1.5; thereof; and at least one polymer capable of reacting with at least the one metal oxide or hydroxide; or a first organic precursor combined with the inorganic phosphate and a second organic precursor combined with the at least one metal oxide or hydroxide, the second organic precursor configured to chemically react with the one or more first organic precursor.

TECHNICAL FIELD

This disclosure relates to metal phosphate hybrid ceramic comprising anorganic phase. In one aspect, the inorganic phosphate ceramiccomposition is prepared from one or more acid-phosphates, one or more ofalkaline metal oxide or metal hydroxide components, and an effectiveamount of one or more polymers or polymeric precursors.

BACKGROUND

Providing waterproofing to ceramic and or cementitious forms or coatingshas proven elusive. Typically, water resisting materials are included inthe pre-set formulation in the desire to have them bloom or migrate tothe surface upon or after setting. Such techniques result in thedissipation of the water repellency properties over time. The basicnature of such materials has resisted most attempts at incorporatingmaterials directly into the ceramic/cement structure without altering,in a negative way, the properties of the ceramic/cement.

SUMMARY

In a first embodiment, an article is provided. The article comprising aninorganic-organic phosphate composition in direct contact with thearticle, the inorganic-organic phosphate composition: at least one metalphosphate phase comprising one or more reaction products of (a) one ormore acid-phosphates representative of one or more of formula (i) or(ii): (i), A_(m)(H₂PO₄)_(m).nH₂O; or (ii) AH₃(PO₄)₂.nH₂O; where A isammonium or a m-valent metal element of m=1, 2, or 3; and n is 0 to 25;and (b) one or more metal oxide or hydroxide represented by either orboth of the formulas B_(2m)O_(m) or B(OH)_(2m), where B is a 2m-valentmetal where m=1 or 1.5; and at least one organic phase layer, whereinthe at least one metal phosphate phase is substantially between the atleast one organic phase layer and the article.

In one aspect, the m-valent metal element of the one or moreacid-phosphates is sodium, potassium, magnesium, calcium, or aluminum.In another aspect, alone or in combination with any of the previousaspects, the m-valent metal element of the one or more metal oxide orhydroxide is magnesium, zinc, calcium, nickel, or copper.

In another aspect, alone or in combination with any of the previousaspects, the organic phase comprises the at least partial reactionproduct of acrylic acid, tartaric acid, citric acid, propionic acid,tannic acid, gallic acid, mellitic acid, pyruvic acid, eugenol, acrylicacid, maleic acid, itaconic acid, alkali earth stearate, or2-ethoxybenzoic acid with the one or more metal oxides or hydroxides.

In another aspect, alone or in combination with any of the previousaspects, the organic phase comprises polyalkanoic acid, polyacrylicacid, polymethacrylic acid, polyhydroxymethylacrylate, polyvinylchloride, polyvinyl acetate, polybutadiene-styrene, carboxylatedpolybutadiene-styrene, nitrile-butadiene, carboxylated nitrilebutadiene, methyl methacrylate butyl acrylate copolymer, polyoxyalkylenealkyl ether, or propylene glycol.

In another aspect, alone or in combination with any of the previousaspects, the organic phase comprises the at least partial reactionproduct of a first organic precursor and a second organic precursor. Inanother aspect, alone or in combination with any of the previousaspects, the at least one first organic precursor is one or morearomatic diisocyanate, aliphatic diisocyanate, polyisocyanate, diepoxy,and polyepoxy. In another aspect, alone or in combination with any ofthe previous aspects, the at least one second organic precursor is oneor more diamine, polyamine, and polyol.

In a second embodiment, a method of forming an inorganic-organicphosphate ceramic is provided. The method comprising combining: (i) atleast one acid-phosphate; (ii) at least one metal oxides or hydroxide;(iii) an organic phase precursor at a loading sufficient to provide atop coat of substantially organic material; and (iii) combining (i) and(ii).

In a first aspect, the at least one acid-phosphate is one or moreacid-phosphates representative of one or more of formula (i),A_(m)(H₂PO₄)_(m).nH₂O or (ii) AH₃(PO₄)₂.nH₂O; where A is ammonium or am-valent metal element; m=1, 2, or 3; and n is 0 to 25; and (b) at leastone sparingly soluble metal oxide represented by the formula B_(2m)O_(m)or B(OH)_(2m), where B is a 2m-valent metal; and m=1 or 1.5.

In another aspect, alone or in combination with any of the previousaspects, the at least one acid-phosphate is at least one of alkali metaldihydrogen phosphate MH₂PO₄, alkali earth dihydrogen phosphate M(H₂PO₄)₂or its hydrate, or mixtures thereof.

In another aspect, alone or in combination with any of the previousaspects, the at least one metal oxide or hydroxide is at least one ofmagnesium oxide, barium oxide, zinc oxide, calcium oxide, copper oxide,and hydroxides thereof, or, independently or in combination, magnesiumbrine containing an effective amount of magnesium hydroxide.

In another aspect, alone or in combination with any of the previousaspects, the at least one acid-phosphate is one or more of monopotassium phosphate, mono calcium phosphate, and their hydrates, and theat least one s metal oxide or hydroxide is one or more of magnesiumoxide, magnesium hydroxide, calcium oxide, or calcium hydroxide.

In another aspect, alone or in combination with any of the previousaspects, the method further comprises combining one or more of aninorganic mineral silicate, wollastonite, talc, amorphous magnesiumsilicate, amorphous calcium silicate, diatomaceous earth,aluminosilicate, olivine, feldspar, calcined Kaolin, mullite, colloidalsilica, silicon dioxide, alumina, or amorphous silicon dioxide.

In another aspect, alone or in combination with any of the previousaspects, the organic phase precursor comprises the at least partialreaction product of acrylic acid, tartaric acid, citric acid, propionicacid, tannic acid, gallic acid, mellitic acid, pyruvic acid, eugenol,acrylic acid, maleic acid, itaconic acid, alkali earth stearate, or2-ethoxybenzoic acid with the one or more metal oxide or hydroxide.

In another aspect, alone or in combination with any of the previousaspects, the organic phase precursor comprises polyalkanoic acid,polyacrylic acid, polymethacrylic acid, polyhydroxymethylacrylate,polyvinyl chloride, polyvinyl acetate, polybutadiene-styrene,carboxylated polybutadiene-styrene, nitrile-butadiene, carboxylatednitrile butadiene, methyl methacrylate butyl acrylate copolymer,polyoxyalkylene alkyl ether, or propylene glycol.

In another aspect, alone or in combination with any of the previousaspects, the organic phase precursor comprises the at least partialreaction product of a first organic precursor and a second organicprecursor. In another aspect, alone or in combination with any of theprevious aspects, the at least one first organic precursor is one ormore aromatic diisocyanate, aliphatic diisocyanate, polyisocyanate,diepoxy, or polyepoxy. In another aspect, alone or in combination withany of the previous aspects, the at least one second organic precursoris one or more diamine, polyamine, or polyol.

In another aspect, alone or in combination with any of the previousaspects, the combining is performed with high shear. In another aspect,alone or in combination with any of the previous aspects, the methodfurther comprises sequentially or concurrently, at least one ofpainting, brushing, troweling, spraying, and vaporizing one or more ofthe at least one acid-phosphate and/or the at least one metal oxide orhydroxide.

In a third embodiment, an inorganic-organic metal phosphate ceramicformed from the presently disclosed method is provided.

In a fourth embodiment, a sprayable inorganic-organic phosphate ceramicprecursor system is provided. The system comprising an aqueous-basedslurry or a suspension, separately comprising components: (a) anaqueous-based slurry or a suspension at least one inorganic phosphaterepresentative of one or more of formula (i), A_(m)(H₂PO₄)_(m).nH₂O or(ii) AH₃(PO₄)₂.nH₂O; where A is ammonium or a m-valent metal element;m=1, 2, or 3; and n is 0 to 25; and (b) at least one metal oxide orhydroxide represented by the formula B_(2m)O_(m) or B(OH)_(2m), where Bis a 2m-valent metal; and m=1 or 1.5; and (c) at least one organic phaseprecursor present at a weight percent of 2-50.

In one aspect, the at least one acid-phosphate is at least one of alkalimetal dihydrogen phosphate MH₂PO₄, alkali earth dihydrogen phosphateM(H₂PO₄)₂ or its hydrate, and mixtures thereof.

In another aspect, alone or in combination with any of the previousaspects, the at least one metal oxide or hydroxide is at least one ofmagnesium oxide, barium oxide, zinc oxide, calcium oxide, copper oxide,nickel oxide, and hydroxides thereof, or, independently or incombination, magnesium brine containing an effective amount of magnesiumhydroxide.

In another aspect, alone or in combination with any of the previousaspects, the at least one acid-phosphate is one or more of monopotassium phosphate, mono calcium phosphate, and their hydrates, and theat least one metal oxide or hydroxide is one or more of magnesium oxide,magnesium hydroxide, calcium oxide, or calcium hydroxide.

In another aspect, alone or in combination with any of the previousaspects, the system further comprises one or more of an inorganicmineral silicate, wollastonite, talc, amorphous magnesium silicate,amorphous calcium silicate, diatomaceous earth, aluminosilicate,olivine, feldspar, calcined Kaolin, mullite, colloidal silica, silicondioxide, amorphous silicon dioxide, alumina, or pigment.

In another aspect, alone or in combination with any of the previousaspects, the organic phase precursor comprises the at least partialreaction product of a C₂-C₅₀ hydrocarboxylic acid, acrylic acid,tartaric acid, citric acid, propionic acid, tannic acid, gallic acid,mellitic acid, pyruvic acid, eugenol, acrylic acid, maleic acid,itaconic acid, alkali earth stearate, or 2-ethoxybenzoic acid with theat least one sparingly soluble metal oxide.

In another aspect, alone or in combination with any of the previousaspects, the organic phase precursor comprises polyalkanoic acid,polyacrylic acid, polymethacrylic acid, polyhydroxymethylacrylate,polyvinyl chloride, polyvinyl acetate, polybutadiene-styrene,carboxylated polybutadiene-styrene, nitrile-butadiene, carboxylatednitrile butadiene, methyl methacrylate butyl acrylate copolymer,polyoxyalkylene alkyl ether, or propylene glycol.

In another aspect, alone or in combination with any of the previousaspects, the organic phase precursor comprises the at least partialreaction product of a first organic precursor and a second organicprecursor. In another aspect, alone or in combination with any of theprevious aspects, the at least one first organic precursor is one ormore aromatic diisocyanate, aliphatic diisocyanate, polyisocyanate,diepoxy, polyepoxy. In another aspect, alone or in combination with anyof the previous aspects, the at least one second organic precursor isone or more diamine, polyamine, or polyol.

In another aspect, alone or in combination with any of the previousaspects, the slurry or the suspension, separately or combined, isconfigured for providing shear thinning during mixing of components (a)or (b) or both of components (a) and (b).

BRIEF DESCRIPTION OF THE DRAWINGS

None

DETAILED DESCRIPTION

The present disclosure provides, among other things, phosphate-based,organic-inorganic hybrid composite coatings having hydrophobicproperties that minimize or reduce the penetration of water and/orcorrosion of metals, for example steels and iron.

Generally, organic materials have and can be applied on top of ceramicsor cementitious material to provide certain properties. Such propertiesare water resistance, stain resistance, crack resistance, and durabilityetc. These techniques result in the lack of benefit of hybrid propertiesat the matrix level, mainly, due to being applied on top of ceramics orcementitious materials and or coatings. Moreover, there is a cleardistinction between organic and inorganic material as organic materialbeing applied on top of inorganic material. Such system does not providebenefit of the presence of organic material within the inorganic matrix.

Hybrid systems can provide synergic properties to the ceramics and orcementitious forms or coatings in terms of physical, mechanical, andchemical properties.

As used herein, the phrases “acidic phosphate component” and“acid-phosphate” and “acid component” and “Part A” are usedinterchangeably unless otherwise indicated. As used herein, the phrase“sparingly soluble acidic phosphate component” refers to inorganicphosphates of chemical formula A_(m)(H₂PO₄)_(m).nH₂O, where A is metalcation, or mixtures thereof; where m=1-3, and n=0-6 having lowsolubility product constants in aqueous media, e.g., e.g., solubilityconstants (Ksp) of at least 10⁻⁴, 10⁻⁵, 10⁻⁶, 10⁻⁷, 10⁻⁸, 10⁻⁹ orsmaller.

As used herein phrases “metal oxide and hydroxide” and “basic component”and “alkaline component” and “alkaline precursor” are usedinterchangeably unless otherwise indicated. The phrases “sparinglysoluble metal oxide or hydroxide” and “sparingly soluble alkalinecomponent” and “sparingly soluble alkaline precursor” are inclusive ofmetal oxide and hydroxide materials that are sparingly soluble, e.g.,have low solubility product constants in aqueous media, e.g., e.g.,solubility constants (Ksp) of at least 10⁻⁴, 10⁻⁵, 10⁻⁶, 10⁻⁷, 10⁻⁸,10⁻⁹ or smaller. In one aspect, the solubility of the metal oxide orhydroxide is less than about 0.1 moles/liter water. In one aspect, thephrases sparingly soluble basic metal oxide and sparingly soluble basicmetal hydroxide component” and “sparingly soluble metal oxide andhydroxide” and “sparingly soluble alkaline component” and “sparinglysoluble alkaline precursor” are exclusive of materials that are readilysoluble, e.g., have high solubility product constants in aqueous media.

As used herein, the product of the “acid-phosphate” and the “metal oxideand hydroxide” provides for a metal phosphate phase having, in oneaspect, have low solubility product constants in aqueous media, e.g.,e.g., solubility constants (Ksp) of 10⁻⁸, 10⁻⁹ or smaller.

As used herein the phrase “organic phase” is associated with one or bothof the acid-phosphate or metal oxide or hydroxide, or, the reactionproduct of the acid-phosphate and the metal oxide or hydroxide (e.g.“the metal phosphate phase”). The term “associated” includes chemicalbonding, ionic or hydrostatic interaction of the organic phase with themetal phosphate phase. While not held to any theory, it is believed theorganic phase provides for an organic-inorganic phosphate coating wherethe organic phase is substantially located at the air-facing surface ofthe coating.

As used herein, the phrase “aqueous mixture” refers to a combination ofat least a quantity of water and at least one of the acid phosphate ormetal oxide or hydroxide. For example, the aqueous mixture can containmostly water and suspended, dispersed, or slurried components, and mayalso contain non-aqueous components such as alcohols and other solvents.Preferably, water is the major liquid phase.

The amount of solids (e.g., the acid phosphate, metal oxide or hydroxideand/or other solids) present in the aqueous mixture can be between 1weight percent to about 95 weight percent, preferably 35-90 weightpercent, or 50-80 weight percent solids.

In addition to the management of the hydrophobicity, the presentdisclosure provides manufacturing methods that optimize the preparationof the acid-phosphates and the metal oxide or hydroxides prior tocombination so as to manage the chemical reactions and/or pH of thechemical reactions of the metallic surface and the acid-phosphates andthe metal oxide or hydroxides. Examples of the inorganic phosphatecoatings provided herein include a magnesium potassium phosphatecoating, and calcium potassium phosphate coating, either of whichoptionally contains the one or more polymers or at least partiallyreacted polymer precursors as discussed above. In one aspect, thecoating comprises the one or more polymers or at least partially reactedpolymer precursors chemically integrated therewith or the reactionproduct of one or more precursors of the polymer. These compositions aredisclosed herein for providing two-part, sprayable metal phosphateceramics, suitable for coating steels, aluminum, and other corrodiblemetals.

It has now been observed that polymers or polymeric precursors, whenadded to one or both of an acid-phosphate/metal oxide or hydroxidephosphate ceramic precursor formulation, are combined or otherwiseformed “in-situ” with an formulation greatly enhance the waterresistance, water proofing, electric isolation, and/or corrosionresistance of the coating.

The above organic-inorganic-phosphate ceramic can be used as monolithicforms, or as coatings that serve as a surface preparation for furthercoating and/or painting, a function it performs effectively withexcellent adhesion. In contrast to the conventional methods ofpassivating/corrosion protecting metal surfaces, the present disclosureprovides improving the metal-phosphate ceramic, reducing its porosityand/or reducing its crystallinity such that the hydrophobicity iscontrolled and/or corrosion preventive aspects, and others, arechemically associated with the metal-phosphate ceramic.

In one aspect, the aqueous mixture of acid-phosphate comprises one ormore acid phosphate salts, optionally comprising one or more hydrophobicagents or hydrophobic precursor components, with or without phosphoricacid, calcined kaolin, and/or colloidal silica, the mixture having a pHbetween about 1 and about 6 (preferably being between about 1.5 to about5, more preferably between about 2 to about 4).

In one aspect, the aqueous mixture of metal oxide or hydroxide comprisesone or more polymers or polymeric precursors. The aqueous mixture ofmetal oxide or hydroxide typically has a pH between about 8 to about 12,preferably about 9 to about 14, more preferably a pH between about 11 toabout 13. The polymers or polymeric precursors can be added alone or incombination with wollastonite, amorphous magnesium silicate, silica,amorphous silicon dioxide, diatomaceous earth, olivine, feldspar and thelike to either or both of the acidic phosphate and the basic metaloxide/hydroxide.

To be clear, such polymers or polymeric precursors are not simply“additives” as they are added at amounts greater than an additive andfunction differently from that of a additive. The polymers or polymericprecursors are added and are intended to chemically combine with eachother to form an oligomeric or a polymeric organic phase. The polymersor polymeric precursors may also combine, to a minor extent, with one ormore of the acid-phosphates, the metal oxide or hydroxide, and/or ametallic surface, and/or the metallic phosphate moieties present and/orcreated.

During the process where the acid-phosphate and the metal oxide orhydroxide form the ceramic, the hydrophobic agents, and in particular,their respective precursor components react or combine to form theoligomeric or polymeric hydrophobic agents. During setting of thephosphate ceramic or a period of time thereafter, the oligomeric orpolymeric hydrophobic agent presents to the outer surface (air-facingsurface) of the object coated so as to provide, among other things, aprotective, mostly organic phase together with a phosphate ceramicphase.

In one aspect, the instant method provides for a treated iron or steelsurface, at least one iron-magnesium-phosphate moiety is believedformed, e.g., a hydrophobic, hydrated magnesium hydrogen iron phosphate,that is chemically distinct from FePO₄ (2H₂O) Fe₃(PO₄)₂ (8H₂O), and/orFe₅H₂(PO₄)₂ (4H₂O) provided by conventional iron phosphating processes,the latter being generally crystalline and porous. Additionalcompositions, including, polyphosphates, and/or amorphous organicpolymeric moieties, as discussed above, as well as inorganicmetal-silicates, can be present and provide additional and/orsynergistic water penetration and/or corrosion protection.

The final pH of the metal phosphate ceramic or a coating prepared fromsame can be provided in the passivation range of steel, e.g., betweenabout pH 9 and about pH 12, between about pH 9.5 and about pH 11.5,between about pH 10.0 and about pH 11.0, between about pH 9.0 and aboutpH 10.5, between about pH 9.5 and about pH 10.0, between about pH 10.0and about pH 10.5. In one aspect, the surface of a coated article can beprovided with a basic nature, for example between about pH 9 and aboutpH 12, between about pH 9.5 and about pH 11.5, between about pH 10.0 andabout pH 11.0, between about pH 9.0 and about pH 10.5, between about pH9.5 and about pH 10.0, between about pH 10.0 and about pH 10.5 toprevent or inhibit bacterial and/or microorganism growth or colonizationon the surface of the coated article. The coated article can be, forexample, a medical article, a ship hull, a vertical or horizontalsurface, or water treatment facility component.

In certain aspects of the present disclosure, the metallic surface isthat of a transition metal or its alloy, for example, iron, chromium,aluminum, copper, etc. Processes and articles prepared therefromdisclosed and described herein overcome many if not all of the problemsrelated to conventional passivation processes of iron, steels, aluminum,and other corrodible metals. The instant processes also provide a moreeconomical, environmentally-friendly method of coating steel and othermetal surfaces with acid-base inorganic phosphate based coatings thatnot only passivate the layer but also provide abrasion resistance alongwith good aesthetics in one step.

The metal phosphate ceramics, when used as a coating as disclosed hereincan comprise, in part, the formation of poly phosphates, and inparticular, poly phosphates formed by phosphites at the interfacialregions of the substrate surface in the instant passivation layer.Polyphosphate alone or in combination with the polymer or reactionproduct of the polymeric precursors can provide impermeablity to waterand humidity, and, independently, can improve corrosion resistance tothe metallic surface. In one aspect, polyphosphates in combination withthe metallic surface and/or interfacial regions of the metal substratecomprise the passivation layer and/or provide water resistance or waterproofing of the ceramic.

Acid-phosphate—The acid-phosphate consists of an acid-phosphaterepresentative of the formula, A_(m)(H₂PO₄)_(m).nH₂O, where A is anm-valent element such as sodium (Na, m=1), potassium (K, m=1), magnesium(Mg, m=2), calcium (Ca, m=2), aluminum (Al, m=3) etc. A may also be areduced oxide phase when higher-valent oxides are used. For example, foriron, which exists in valence state of +2 and +3 (FeO and Fe₂O₃ asoxides), A can be the metal of lower oxidation state. It can also be acation of oxides of four-valent metal oxide such as ZrO²⁺, in which casem=2. nH₂O in the formula above is the bound water, where n can be 0 orany number, normally ranging from 0 to 25.

It is possible to use hydro phosphates of trivalent metals such asaluminum, iron and manganese represented by the formula AH₃(PO₄)₂.nH₂O,where A is a transition metal that includes aluminum, iron, manganese,yttrium, scandium, and all lanthanides such as lanthanum, cerium, etc.

Metal oxide or hydroxide—The metal oxide or hydroxide can include forexample, basic oxides, hydroxides and basic minerals. In one aspect, themetal oxide or hydroxide is “sparingly soluble” e.g., an oxide andhydroxide with a solubility product constant less than the acidphosphate precursor. The oxide or hydroxide may be represented by theformula B_(2m)O_(m) or B(OH)_(2m), where B is a 2m-valent metal. Alldivalent metal oxides (m=1), and some trivalent metal oxides (m=1.5) inreduced state fall into this category of small solubility productconstant oxides. Examples of divalent oxides are, but not limited to,magnesium oxide, barium oxide, zinc oxide, calcium oxide and copperoxide. Examples of trivalent oxides in reduced state are iron oxide(FeO), and manganese oxide (MnO). In preferred aspects of the instantdisclosure, 0 to about 10 molar excess of metal oxide or hydroxiderelative to acidic component is used. For example, about 0.1-10 molarexcess of Mg(OH)₂ based on MKP acid phosphate can be used. In oneaspect, the molar ratio of acid:base components can be between about0.9:1.0 to about 1.0:3.0; preferably about 1.0:2.0; and most preferably,about 1.0:1.8. For example, the composition comprisingMg(OH)₂:KH₂PO₄=1.8:1.0 provides equal volumes of Parts A and B duringspraying. In other aspects, spray coatings of the instant compositionshaving a molar ratio of about 1:2 or about 1:1.5 (acid:base components)with mixing, sprayed well and corrosion-protected and/or water proofedeffectively.

In case the pH of the acidic precursor is higher than needed for instantreaction, phosphoric acid may be added and the pH may be adjusted tobring down the pH. A preferred pH selected is between 3 and 4, and themost preferred pH is between 3 and 3.5. either elevating the pH ofphosphoric acid or that of an acid-phosphate such as magnesiumdihydrogen phosphate (Mg(H₂PO₄)₂) or aluminum trihydrogen phosphate(AlH₃(PO₄)₂) by neutralizing partially using an alkaline oxide,hydroxide, or a mineral, or by acidifying a dihydrogen phosphate such asmono potassium phosphate (KH₂PO₄) that has a pH>3.5 by adding a smallbut appropriate amount of phosphoric acid or a low pH acid phosphatesuch as Mg(H₂PO₄)₂ or aluminum trihydrogen phosphate AlH₃(PO₄)₂.

One or more of the components (acid-phosphate or metal oxide orhydroxide) of the instant composition can be wet milled to an averageparticle size of about 1 to about 150 micron, or to about 1 to about 100micron, or to about 5 to about 50 micron or about to −25 micron. In oneaspect, the acidic phosphate or basic precursor is wet-milled so thatthe average particle size passes through 230 mesh sieve (less than 70micron). To improve atomization and/or cure/set and/or appearancequalities of the coating and to reduce or eliminate pit-defects in thecoating, a small average particle size for the metal oxide or hydroxideis used, for example, 1 micron to less than 50 micron, or 1 micron toless than 25 micron.

In one aspect, to achieve a desired setting rate and prevent sagging ofa coating prepared from the hydrophobic phosphate ceramic disclosedherein, about 30-50 weight percent basic metal oxide/hydroxide and about55-75 weight percent acid-phosphate can be used. In one preferredaspect, about 40 weight percent magnesium hydroxide and about 62 weightpercent mono potassium phosphate can be used. Other loadings may be usedfor coating horizontal surfaces.

For reasons not entirely understood, when the acidic component isphosphoric acid and the metal oxide or hydroxide is sparingly solubleand used in a stoichiometric amount greater than 10% of theacid-phosphate, corrosion resistance is less than that when using theacidic phosphate/metal oxide or hydroxides herein disclosed, inparticular, sparingly soluble acid/base components. Thus, in one aspect,improvement in corrosion protection is achieved when both phosphoricacid as the inorganic acidic phosphate and iron oxide as the metal oxideprecursor are excluded.

In another aspect, the instant compositions, either as bulk forms or ascoatings can be formulated to provide aesthetic properties, such ascolor, proper shine, and texture. This effect may be achieved, forexample, by adding pigments, color aggregate, crushed glass, sand, etc,to the instant acidic phosphate/alkaline metal oxide/hydroxideformulations. For example, the resulting coating comprising crushedglass prepared by the processes disclosed herein provides a very dense,glassy surface. Additional suitable ceramic pigments may be furtheradded to produce colored paints. Soluble glass in combination with theinstant compositions above can also be used in formulations for coatingof solid objects, to provide very dense, glassy solid coatings havingcorrosion resistance.

In one aspect, the instant compositions can be configured as separate,atomizible, sprayable inorganic phosphate precursors that can be sprayedat a relatively thin thickness. The compositions can hold high solidscontents and yet still hold the solids until setting and thus avoidingthe solids migrating or dislodging from the point of application, e.g.,down a wall, beam, curved surface, or from a ceiling surface. Such spraycoated phosphate ceramic compositions produce high-strength,rapid-setting phosphate ceramic coatings that provide corrosionprotection and/or be used as an undercoating in combination with apolymeric coating or paint, such as an acrylic- or urethane-basedcoating or paint. In one aspect, said phosphate spray coatingcompositions are suitable for spray coating on metal surfaces, forexample, structural elements and chassis of transportation vehicles suchas automobiles, trains, cycles, aerospace vehicles, trucks, and buses.Methods of providing Part A and Part B compositions and equipmentsuitable for high-shear mixing and spraying of the phosphate ceramicmaterials disclosed herein is disclosed in co-assigned U.S. PatentApplication Publication No. 2011/0143910, which is incorporated byreference in its entirety.

In one aspect, the atomizable phosphate ceramic composition can comprisean acid-phosphate comprising an aqueous solution, suspension, or slurryof an acid-phosphate, for example, of chemical formulaA_(m)(H₂PO₄)_(m).nH₂O, where A is hydrogen ion, ammonium cation, metalcation, or mixtures thereof; where m=1-3, and n=0-6; the first componentsolution adjusted to a pH of about 2 to about 5; a metal oxide orhydroxide, comprising, for example, an aqueous solution, suspension, orslurry of an alkaline oxide or alkaline hydroxide represented byB_(2m)O_(m), B(OH)_(2m), or mixtures thereof, where B is an element ofvalency 2m (m=1, 1.5, or 2) the second component solution adjusted to apH of between 9-14.

Optionally, a rheology modifier/suspending agent in an amount capable ofproviding shear thinning of either the first component or the secondcomponent and further capable of suspending a high solids content ofeither the first component or the second component for atomization canbe added. In one aspect, the rheology modifier is added in an amount of0.01 to about 10 weight percent of the composition. The rheologymodifier/suspending agent can be at least one of guar gum, diutan gum,welan gum, and xanthan gum. By using a rheology modifier/suspendingagent in an amount capable of providing shear thinning of either theacidic component or the metal oxide or hydroxide and further capable ofsuspending a high solids content of either the acidic component or themetal oxide or hydroxide for atomization, excellent paint-like coatingsfor imparting corrosion resistance to metallic surfaces are obtained.

Optionally, pigments and/or aggregate material can be present in anamount in at least one of the acidic phosphate and the metal oxide orhydroxide capable of imparting an observable color and/or texture. Theabove atomizible spray coating can provide a thin, paint-like coatingfor imparting hydrophobicity and/or corrosion resistance to metallicsurfaces.

Water may be added to the precursor component to reduce the viscositythereof, or other types of viscosity reducing agents and/or rheologymodifiers may be used. Commercial additives that prevent algae growthmay also added to this precursor so that no algae growth occurs duringstorage of this precursor.

Experimental Section

The following examples are illustrative of the embodiments presentlydisclosed, and are not to be interpreted as limiting or restrictive. Allnumbers expressing quantities of ingredients, reaction conditions, andso forth used herein may be understood as being modified in allinstances by the term “about.” Accordingly, unless indicated to thecontrary, the numerical parameters set forth herein may beapproximations that may vary depending upon the desired propertiessought to be obtained. At the very least, and not as an attempt to limitthe application of the doctrine of equivalents to the scope of anyclaims in any application claiming priority to the present application,each numerical parameter should be construed in light of the number ofsignificant digits and ordinary rounding approaches. Severalexperimental examples, listed below, were conducted in order toformulate, coat, and demonstrate the attributes of the instantcompositions disclosed herein. pH values are provided using pH metershaving +/−0.5 accuracy.

Examples of aromatic diisocyanates for mixing with Part A include1,3-phenylene diisocyanate; 1,4-phenylene diisocyanate; 2,6-toluenediisocyanate; 2,4-toluene diisocyanate; 80% 2,4-TDI; 20% 2,6-TDI, blendof isomers; naphthalene, 1,5-diisocyanato; diphenyl oxide4,4′-diisocyanate; 4,4′-methylenediphenyl diisocyanate;2,4′-methylenediphenyl diisocyanate; 2,2′-diisocyanatodiphenylmethane;diphenylmethanediisocyanate; 3,3′-dimethyl-4,4′-biphenylene isocyanate;3,3′-dimethoxy-4,4′-biphenylene diisocyanate; benzene,1-[(2,4-diisocyanatophenyl)methyl]-3-isocyanato-2-methyl; and2,4,6-triisopropyl-m-phenylene diisocyanate.

Examples of aromatic multi-isocyanates for mixing with Part A include2,4-toluenediisocyanate dimer; tris(4-isocyanatophenyl) thiophosphate;4,4′,4″-triisocyanatotriphenylmethane; 2,4-toluene diisocyanate trimer;1,3-diazetidine-2,4-dione,1,3-bis[4-[(2-isocyanatophenyl)methyl]phenyl];1,3-diazetidine-2,4-dione,1,3-bis[4-[(4-isocyanatophenyl)methyl]phenyl]; 4,4-MDI uretidinone; andpolymethylenepolyphenyl polyisocyanate.

Examples of aliphatic-aromatic isocyanates for mixing with Part Ainclude 1,4-xylylene diisocyanate; 1,3-xylylene diisocyanate;1,3-bis(1-isocyanato-1-methylethyl)benzene; and1,4-bis(1-isocyanato-1-methylethyl)benzene.

Examples of aliphatic diisocyanates for mixing with Part A include1,6-hexamethylene diisocyanate; 1,5-diisocyanato-2-methylpentane; methyl2,6-diisocyanatohexanoate, bis(isocyanatomethyl)cyclohexane;1,3-bis(isocyanatomethyl)cyclohexane; 2,2,4-trimethylhexane1,6-diisocyanate; 2,4,4-trimethylhexane 1,6-diisocyanate;2,5(6)-bis(isocyanatomethyl)bicyclo[2.2.1]heptane;1,3,3-trimethyl-1-(isocyanatomethyl)-5-isocyanatocyclohexane;1,8-diisocyanato-2,4-dimethyloctane;octahydro-4,7-methano-1h-indenedimethyl diisocyanate,1,1′-methylenebis(4-isocyanatocyclohexane) and hexanoic acid,[[2-ethyl-2-[[[[[5-isocyanato-1(or5)-(methoxycarbonyl)pentyl]amino]carbonyl]oxy]methyl]-1,3-propanediyl]bis(oxycarbonylimino)]bis[isocyanato-,dimethyl ester.

Examples of aliphatic multi-isocyanates for mixing with Part A include,hexamethylene diisocyanate dimer; hexamethylene diisocyanate biuret;hexamethylene diisocyanate isocyanurate; 1,3,5-triazine-2,4,6(1H,3H,5H)-trione,1,3,5-tris[(5-isocyanato-1,3,3-trimethylcyclohexyl)methyl]; and1,3-propanediol,2-ethyl-2-(hydroxymethyl)-5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane.

Examples of precursors for mixing with Part B include diols, triols,tetraols, polyols, phenols, polymer polyols, diamines, triamines andpolyamines. Epichlorohydrine and epoxides from ethylene oxide,alkyloxides, or polymer polyols.

Examples of amines and polyamines include ethanolamine; diethanolamine;propanolamine; triethanolamine; ethylene diamine; diethylenetriamine;triethylenetetramine; 2-methylimidazole, imidazole; aniline-formaldehydemethylenedianiline; toluenediamine; n-(2-aminoethyl)piperazine; and4,4′-diaminodiphenylmethane.

Examples of diol, triols, polyols, polymer polyols and other compoundsinclude ethyleneglycol; 1,4-butanediol/THF; 1,4-butanediol/THF;neopentyl glycol; butylene oxide; glycerol; trimethylolpropane;trimethylolpropane, propylene glycol; pentaerythritol; sorbitol,mannitol; sorbitol, mannitol; sorbitol, mannitol; sucrose; phenol;bisphenol A; tetrabromo bisphenol A; nonylphenol, formaldehyde;p-t-butyl phenol, formaldehyde; phenol formaldehyde;bis[4-(2-hydroxypropoxy)phenyl]sulfone; phenol, formaldehyde,1,2-propylene glycol; toluenediamine; toluenediamine, propylene glycol;glycerol, allyl glycidyl ether, trimethylolpropane polymer;epichlorohydrine; epichlorohydrine; epichlorohydrine; and castor oil,hydrogenated.

The polymer and polymeric precursors can be used amounts of about 2weight percent to about 50 weight percent, or about 5 weight percent toabout 40 weight percent, or about 7 weight percent to about 35 weightpercent. Addition of other hydrophobic agents than those describedabove, in the acidic phosphate and/or metal oxide or hydroxidecomposition, can be employed, such as polysilicones, polysiloxanes,etc., in small amounts, e.g., less than 2 weight percent.

Organic-Inorganic Phosphate Coating Compositions

A range of phosphate compositions may be used as t coatings commensuratewith the spirit and scope of that disclosed and described herein.

TABLE 1 Exemplary Phosphate Ceramic Composition Part A Part B Sam-Weight percent Weight percent ple (%) of Part A (%) of Part B A monopotassium phosphate magnesium hydroxide (25- (MKP) (40-65%) 50%)phosphoric acid (1-8%) wollastonite (10-25%) colloidal silica (1-10%)xanthan gum (0.07%) diisocyanate monomer (5-30%) Polyol monomer (5-30%)remainder water remainder water B mono potassium phosphate magnesiumhydroxide (~38- (MKP) (~63-64%) 39%) phosphoric acid (~8%) wollastonite(~20-21%) xanthan gum (0.15%) xanthan gum (0.07%) diisocyanate monomer(6-25%) Polyamine monomer (~5-25%) remainder water Filler (~40-60%)remainder water

In one exemplary sprayable composition commensurate with that summarizedin Table 1, 9 w % diisocyanate was added to Part A (MKP) and 10 w %polyol was added to Part B (MgOH at 38-40 weight percent) prior tomixing and spraying. This loading of first and second organicprecursors, when separately mixed and sheared with its correspondingPart A or Part B was spray coated on a corrodible surface, and provideda top layer comprising substantially polymeric isocyanate.

In another exemplary sprayable composition commensurate with thatsummarized in Table 1, 20 w % diisocyanate was added to Part A (MKP) and25 w % polyamine was added to Part B (MgOH at 38-40 weight percent)prior to mixing and spraying. This loading of first and second organicprecursors, when separately mixed and sheared with its correspondingPart A or Part B was spray coated on a corrodible surface, and provideda top layer comprising substantially polymeric urea. The nature of thediisocyanate and the polyol and/or polyamine can be adjusted (e.g.,hydrocarbon content, functionality, aromaticity/aliphalicity etc.) tomanipulate the properties of the compatibility and/or stability of thepolymer precursors in the respective Part A/Part B, or to manipulate theproperties of the organic phase and the topcoat properties of theorganic-inorganic phosphate coating.

The cross-sectional compositional make-up of such a coating comprises,starting from the corrodible surface, is a passivation layer, apredominately inorganic phase layer of phosphate ceramic, and a toplayer of substantially organic composition. In practice, the loading offirst and second organic precursors will depend on the polymer systemdesired, the relative thickness of topcoat desired, the pigment loadingneeded, and the molecular weight of the precursors.

It was also observed that the of first and second organic precursorsprovided improved loading of pigment, more than can be loaded ascompared to a conventional polymer based paint or coating, for example.Generally speaking, conventional, non-ceramic based paint and coatingsystems are characterized based on PVC (Pigment Volume Concentration)and CPVC (Critical Pigment Volume Concentration). PVC is understood tomean Pigment Volume of Pigment+Filler/Total Volume of Dry Coating. CPVCis a value, expressed as a ratio, of where there is just sufficientbinder to coat the pigment surfaces and fill voids between pigmentparticles. In the present disclosure, the inorganic-organic phosphateceramic is capable of higher loadings (e.g., 10%, 20%, 30%, or more than40% higher wt. %) of pigment and/or filler than conventional non-ceramicbased paint. While not to be held to any theory, it is believed that theorganic component or phase of the inorganic-organic phosphate ceramic,which may chemically or otherwise associate with the phosphate ceramicconstituents, provides more binder volume to the total volume of the drycoating and hence, provides more volume for the filler/pigment.Polymer-based paint and coatings systems typically cannot have fillermore than a certain weight percentage (based on PVC and CPVC) becausefillers/pigments do not participate in the film formation of suchconventional coatings. On the other hand, the present compositions,comprising inorganic-organic hybrid systems comprise at leasttwo-phases, at least one of which can be a binding phase for thefiller/pigment while also binding to the filler/pigment. There may besome organic-inorganic binding phases as well in the presently disclosedcompositions to accommodate higher loading of pigment/filler. Thus, thepresent compositions allows wide ranges of compositional loadings offillers, pigments, etc., as the PVC and CPVC conventions as forconventional paints/coatings may not apply, for example, such that thePigment Volume Concentration (PVC) that is greater than 0.5 to about 0.7and the Critical Pigment Volume Concentration that is greater than 0.6to less than 1.0.

1. An article comprising an inorganic-organic phosphate composition indirect contact with the, the inorganic-organic phosphate compositioncomprising: (i) at least one metal phosphate phase comprising one ormore reaction products of (a) one or more acid-phosphates representativeof one or more of formula (i) or (ii):A_(m)(H₂PO₄)_(m) .nH₂O; or  (i)AH₃(PO₄)₂ .nH₂O;  (ii) where A is ammonium or an m-valent metal element;m=1,2, or 3; and n is 0 to 25; and (b) one or more bases represented byeither or both of the formulas B_(2m)O_(m) or B(OH)_(2m), where B is a2m-valent metal where m=1 or 1.5; and (ii) at least one organic phaselayer; wherein the at least one metal phosphate phase is substantiallybetween the at least one organic phase layer and the article.
 2. Thearticle of claim 1, wherein the m-valent metal element of the one ormore acid-phosphates is sodium, potassium, magnesium, calcium, barium,zinc, nickel, copper or aluminum.
 3. (canceled)
 4. The article of claim1, wherein the organic phase layer comprises at least a partial reactionproduct of acrylic acid, tartaric acid, citric acid, propionic acid,tannic acid, gallic acid, mellitic acid, pyruvic acid, eugenol, acrylicacid, maleic acid, itaconic acid, alkali earth stearate, or2-ethoxybenzoic acid with the one or more bases.
 5. The article of claim1, wherein the organic phase layer comprises polyalkanoic acid,polyacrylic acid, polymethacrylic acid, polyhydroxymethylacrylate,polyvinyl chloride, polyvinyl acetate, polybutadiene-styrene,carboxylated polybutadiene-styrene, nitrile-butadiene, carboxylatednitrile butadiene, methyl methacrylate butyl acrylate copolymer,polyoxyalkylene alkyl ether, or propylene glycol.
 6. (canceled)
 7. Thearticle of claim 1, wherein the at least one organic phase layercomprises at least a partial reaction product of one or more aromaticdiisocyanate, aliphatic diisocyanate, polyisocyanate, diepoxy, polyepoxyand one or more diamine, polyamine, or polyol.
 8. (canceled)
 9. A methodof forming an inorganic-organic phosphate ceramic, the method comprisingcombining: (i) at least one acid-phosphate; (ii) at least one basicoxide or hydroxide component; and (iii) an organic phase precursor at aloading sufficient to provide a top coat of substantially organicmaterial.
 10. The method of claim 9, wherein the at least oneacid-phosphate is one or more acid-phosphates representative of one ormore of formula (i), A_(m)(H₂PO₄)_(m).nH₂O, (ii) AH₃(PO₄)₂.nH₂O; where Ais ammonium or an m-valent metal element; m=1, 2, or 3; and n is 0 to25; and (B) the one or more basic oxide or hydroxide is represented bythe formula B_(2m)O_(m) or B(OH)_(2m), where B is a 2m-valent metal; andm=1 or 1.5.
 11. The method of claim 9, wherein the at least oneacid-phosphate is at least one of alkali metal dihydrogen phosphateMH₂PO₄, alkali earth dihydrogen phosphate M(H₂PO₄)₂ or its hydrate, ormixtures thereof and wherein the at least one basic oxide or hydroxideis magnesium oxide, barium oxide, zinc oxide, calcium oxide, copperoxide, and hydroxides thereof, or, independently or in combination,magnesium brine containing an effective amount of magnesium hydroxide.12. (canceled)
 13. The method of claim 9, wherein the at least oneacid-phosphate is one or more of mono potassium phosphate, mono calciumphosphate, and their hydrates, and the at least one basic oxide orhydroxide is magnesium oxide, magnesium hydroxide, calcium oxide, orcalcium hydroxide.
 14. The method of claim 9, further comprisingcombining one or more of an inorganic mineral silicate, wollastonite,talc, amorphous magnesium silicate, amorphous calcium silicate,diatomaceous earth, aluminosilicates, olivine, feldspar, calcinedKaolin, mullite, colloidal silica, silicon dioxide, or amorphous silicondioxide with (i) or (ii).
 15. The method of claim 9, wherein the organicphase precursor comprises the at least partial reaction product ofacrylic acid, tartaric acid, citric acid, propionic acid, tannic acid,gallic acid, mellitic acid, pyruvic acid, eugenol, acrylic acid, maleicacid, itaconic acid, alkali earth stearate, or 2-ethoxybenzoic acid with(ii).
 16. The method of claim 9, wherein the organic phase precursorcomprises polyalkanoic acid, polyacrylic acid, polymethacrylic acid,polyhydroxymethylacrylate, polyvinyl chloride, polyvinyl acetate,polybutadiene-styrene, carboxylated polybutadiene-styrene,nitrile-butadiene, carboxylated nitrile butadiene, methyl methacrylatebutyl acrylate copolymer, polyoxyalkylene alkyl ether, or propyleneglycol.
 17. (canceled)
 18. The method of claim 9, wherein the organicprecursor comprises at least a partial reaction product of one or morearomatic diisocyanate, aliphatic diisocyanate, polyisocyanate, diepoxy,polyepoxy and one or more diamine, polyamine, or polyol.
 19. (canceled)20. (canceled)
 21. An inorganic-organic metal phosphate ceramic formedfrom the method of claim
 9. 22. A sprayable inorganic-organic phosphateceramic precursor system comprising: an aqueous-based slurry or asuspension, separately comprising components: (a) an aqueous-basedslurry or a suspension at least one inorganic phosphate representativeof one or more of formula (i), A_(m)(H₂PO₄)_(m).nH₂O or (ii)AH₃(PO₄)₂.nH₂O; where A is an m-valent metal element; m=1, 2, or 3; andn is 0 to 25; and (b) at least one basic oxide or hydroxide representedby the formula B_(2m)O_(m) or B(OH)_(2m), where B is a 2m-valent metal;and m=1 or 1.5; and (c) at least one organic phase precursor present ata weight percent of 2 to
 50. 23. The system of claim 22, wherein the atleast one acid-phosphate is at least one of alkali metal dihydrogenphosphate MH₂PO₄, alkali earth dihydrogen phosphate M(H₂PO₄)₂ or itshydrate, and mixtures thereof.
 24. The system of claim 22, wherein theat least one basic oxide or hydroxide is magnesium oxide, barium oxide,zinc oxide, calcium oxide, copper oxide, and hydroxides thereof, or,independently or in combination, magnesium brine containing an effectiveamount of magnesium hydroxide and, wherein the at least oneacid-phosphate is one or more of mono potassium phosphate, mono calciumphosphate, and their hydrates, and the at least one basic oxide orhydroxide is magnesium oxide, magnesium hydroxide, calcium oxide, orcalcium hydroxide.
 25. (canceled)
 26. The system of claim 22, furthercomprising one or more of an inorganic mineral silicate, wollastonite,talc, amorphous magnesium silicate, amorphous calcium silicate,diatomaceous earth, aluminosilicate, olivine, feldspar, calcined Kaolin,mullite, colloidal silica, silicon dioxide, amorphous silicon dioxide,or pigment.
 27. The system of claim 22, wherein the organic phaseprecursor comprises at least a partial reaction product of acrylic acid,tartaric acid, citric acid, propionic acid, tannic acid, gallic acid,mellitic acid, pyruvic acid, eugenol, acrylic acid, maleic acid,itaconic acid, alkali earth stearate, or 2-ethoxybenzoic acid with theat least one basic oxide or hydroxide.
 28. The system of claim 22,wherein the organic phase precursor comprises polyalkanoic acid,polyacrylic acid, polymethacrylic acid, polyhydroxymethylacrylate,polyvinyl chloride, polyvinyl acetate, polybutadiene-styrene,carboxylated polybutadiene-styrene, nitrile-butadiene, carboxylatednitrile butadiene, methyl methacrylate butyl acrylate copolymer,polyoxyalkylene alkyl ether, or propylene glycol.
 29. (canceled)
 30. Thesystem claim 22, wherein the organic phase precursor comprises at leasta partial reaction product of one or more aromatic diisocyanate,aliphatic diisocyanate, polyisocyanate, diepoxy, polyepoxy and one ormore diamine, polyamine, or polyol.
 31. (canceled)